Design rules for web crippling of stainless steel tubular sections at elevated temperatures are currently unavailable. In this study, non-linear finite element models (FEMs) were developed for the web crippling of cold-formed lean duplex stainless steel (CFLDSS) square and rectangular hollow sections under the concentrated end bearing loads, namely the loading conditions of End-One-Flange (EOF), End-Two-Flange (ETF) and End Loading (EL). After successful validation of the FEMs, an extensive parametric study of 210 CFLDSS tubular sections at elevated temperatures (up to 950 °C) was performed. The appropriateness of the web crippling design rules in the current international specifications and literature was examined by comparing their ultimate strength predictions with those obtained from the parametric study. The material properties at room (ambient) temperature condition were substituted by those at elevated temperatures. It was found that the predictions by the current design specifications and the literature were generally unconservative and not reliable, while the European Code provided reliable but generally very conservative predictions. A new design method by using the Direct Strength Method was proposed for the web crippling of CFLDSS tubular sections at elevated temperatures under the loading conditions of EOF, ETF and EL. The assessments indicated that the predictions by using the new method were generally conservative and reliable.

目前尚无用于在高温下对不锈钢管段进行腹板折皱的设计规则。在这项研究中，开发了非线性有限元模型（FEMs），用于在集中的端部载荷作用下，即在第一端的载荷条件下，冷弯的贫双相不锈钢（CFLDSS）方形和矩形空心截面的腹板瘫痪-法兰（EOF），两端二法兰（ETF）和末端加载（EL）。在对FEM进行成功验证之后，在高温（最高950°C）下对210 CFLDSS管状截面进行了广泛的参数研究。通过将其极限强度预测与从参数研究中获得的极限强度预测进行比较，研究了当前国际规格和文献中的网状折断设计规则的适用性。室温（环境）条件下的材料性能被高温下的材料性能所替代。已经发现，当前设计规范和文献中的预测通常是不保守且不可靠的，而欧洲法规提供了可靠但通常非常保守的预测。提出了一种采用直接强度法的新型设计方法，用于在EOF，ETF和EL的加载条件下，在高温下CFLDSS管段的腹板瘫痪。评估表明，使用新方法进行的预测通常是保守和可靠的。而《欧洲规范》则提供了可靠但通常非常保守的预测。提出了一种采用直接强度法的新型设计方法，用于在EOF，ETF和EL的加载条件下，在高温下CFLDSS管段的腹板瘫痪。评估表明，使用新方法进行的预测通常是保守和可靠的。而《欧洲规范》则提供了可靠但通常非常保守的预测。提出了一种采用直接强度法的新型设计方法，该方法在EOF，ETF和EL的加载条件下，对CFLDSS管状截面在高温下的腹板瘫痪进行了研究。评估表明，使用新方法进行的预测通常是保守和可靠的。